The keima connection is an efficient shape. It assumes any cutting stone can be captured, typically with a ladder or possibly a loose ladder.
unkx80: Extra line?
Yes, why not ? ;-) we could also be in the center and not in a corner even if these rectangular shapes are much seen in corners
unkx80: Okay... I added the stone. These diagrams are a bit confusing for me.
Careful, not to put the group in atari.